Possible Causes & Corrections
WARNING: This page is about a different car, the 2003 GMC Sierra and 2003 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
Check the following items:
- Compare customer vehicle with a similar unit. Verify the customer's concern.
- Remove air filter and check for dirt or a restriction.
- Inspect transmission shift pattern and downshift operation.
- Inspect for a restricted fuel filter, contaminated fuel, or improper fuel pressure. See FUEL SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - 4.3L SIERRA & SILVERADO article.
- Perform the fuel injector balance test. See FUEL SYSTEMS in SYSTEM & COMPONENT TESTING - 4.3L SIERRA & SILVERADO article.
- Inspect exhaust system for a possible restriction. See RESTRICTED EXHAUST .
- Inspect exhaust system for damaged or collapsed pipes. Inspect the muffler for heat distress or a possible internal failure.
- Inspect control module grounds for being clean, tight, and in their proper location.
- Inspect Torque Converter Clutch (TCC) operation. See appropriate DIAGNOSIS in AUTOMATIC TRANSMISSIONS article.
- Inspect A/C operation. See appropriate MANUAL or AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING.
- Test generator output voltage.
- Monitor Knock Sensor (KS) system for retarded timing. See DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - 4.3L SIERRA & SILVERADO article.
- Engine compression. See CYLINDER COMPRESSION PRESSURE under MECHANICAL INSPECTION under PRELIMINARY INSPECTION & ADJUSTMENTS in BASIC DIAGNOSTIC PROCEDURES - 4.3L SIERRA & SILVERADO article. Low compressions can be caused by faulty valve timing or improper or worn camshaft.